Lasing below 200 nm in the NIJI-IV compact storage-ring-based free electron laser

Laser gain of the NIJI-IV compact storage-ring-based Free Electron Laser (FEL) system at AIST reached ∼9% at 200 nm for an average beam current of 16.3 mA. In addition to such a drastic gain enhancement, improvement of the laser-cavity performance has led to successful FEL lasing in the vacuum ultraviolet below 200 nm even in a compact system. Temporal and spectral characteristics of the NIJI-IV FEL were examined around 200 nm. FEL performance will be briefly discussed from the application point of view.